Bolivian president Evo Morales holds a coca leaf as he addresses the 61st session of the U.N. General Assembly at the United Nations headquarters,

UNITED NATIONS -- Bolivian president Evo Morales brandished a coca leaf on the floor of the United Nations Tuesday in a passionate rebuke of U.S. criticisms of the South American nation's anti-drug policies.

The State Department on Monday included Bolivia in its annual list of major drug-transit or drug-producing countries, singling out Morales' government for continuing to permit the legal harvest of coca, the principal ingredient in cocaine.

Morales, a former coca-grower elected in December as Bolivia's first indigenous president, surprised the U.N. General Assembly by pulling out the small leaf _ banned in the United States _ and holding it aloft.

"Coca is green, not white like cocaine," he said, to a smattering of applause. "Scientifically ... it has been demonstrated that the coca leaf does no harm to human health."

Morales has upped his government's enforcement efforts against cocaine production while continuing to promote coca's legal use in tea, medicines and other products.

U.S. Deputy Assistant Secretary of State Christy McCampbell on Monday expressed "very serious concerns" about the effectiveness of Morales' coca policy. She reiterated demands for a more thorough eradication program, the development of alternative crops and an overhaul of Bolivian drug laws.

McCampbell said that the U.S. would review Bolivia's drug policies again in six months' time.

Without significant change in the Morales' program, Bolivia could face decertification _ the loss of some $100 million in U.S. government aid in the fight against narco-trafficking.

"With all respect to the government of the United States, we are not going to change anything. We do not need blackmail or threats," Morales said. "Certification or decertification is an instrument of recolonization, or colonization, of the Andean countries. That we will not accept."